clinton we know that during an earlier illness she became light-headed, fainted and then hit her head and cuncussed. could it be a side effect of the concussion. >> concussion in adults it is not a known cause of venous signus thrombosis. in children sometimes it makes them sus-- susceptible. and given it is an uncommon condition, five in a million it is not a common condition at all. so i doubt it was directly related to concussion because in general, it is not known to be caused by that. but among possible causes, again, you are allowed it to speculate, it would be ruled out some of them like pregnancy or if there is any tendency of a blood disorder, a tendency to hypercoagulate,. >> suarez: so what do we do in treatment? and is it a long course of treatment? >> yes and no. if there is, for example n someone pregnant or just gave birth and maybe has thrombosis, about three to six months of anti-coagulation or using blood thinners would be enough. if there is no particular cause, the range from 6 to 12 months. and there are conditions when it is unlimited. so to some extent it depend